The exposures are wide and varied for firefighters. Overall, just so you understand, we carry a high body burden of toxins, chemicals and carcinogens. The respiratory route of exposure is still real and still there. A lot of the work done by Dr. Ken Fent and Dr. Gavin Horn has shown that the hazardous zone outside of the internal structure has lots of particulate matter, polycyclic aromatic hydrocarbons and volatile organics, so even the firefighters operating from the exterior of a structure fire are exposed.
We're also really good at harvesting and depositing contaminants, and studies on fire stations note that there are a number of polybrominated flame retardants and PFAS chemicals being deposited in fire stations, as well as heavy metals and a lot of PAHs. That is problematic because there is a sense that wearing a self-contained breathing apparatus will protect you.
We have seen a lot of new studies with respect to dermal exposure specifically. Jennifer Kerr just published one recently, this month, showing the high rates of polycyclic aromatic hydrocarbon metabolites found in the urine, with the expectation that those have been absorbed within seconds or minutes of being inside a structure.
We don't have the opportunity to engineer out these exposures as firefighters. We're going to be exposed to them. As mentioned last week, there are PFAS chemicals in our bunker gear. There are PFAS chemicals in AFFF use. There are all sorts of routes from absorption, inhalation and ingestion.